Synthesis and characterization of four organic–inorganic salts: sulfates of 2-aminopyridinium derivatives

Abstract

Hybrid materials, fabricated by the combination of inorganic and organic components, have potential applications in chemistry and are endowed with the advantages of both building elements. There are several types of intermolecular interactions present in these hybrid compounds, including electrostatic forces, π–π stacking and hydrogen-bonding interactions, the latter playing an important role in the construction of three-dimensional architectures and stabilizing supramolecular crystal structures. Analysis of the intermolecular interactions and their influence on packing modes therefore requires focused scientific attention. Four new organic–inorganic salts, namely 2-amino-4-methyl-3-nitropyridinium hydrogen sulfate, C6H8N3O2+·HSO4−, bis(2-amino-4-methyl-3-nitropyridinium) sulfate, 2C6H8N3O2+·SO42−, 2-amino-3-methylpyridinium hydrogen sulfate, C6H9N2+·HSO4−, and bis(2-amino-3-methylpyridinium) sulfate monohydrate, 2C6H9N2+·SO42−·H2O, have been synthesized and characterized by X-ray diffraction. The crystal structures are stabilized by intra- and intermolecular hydrogen bonds, as well as by weak π–π stacking and lp–π (lp is lone pair) interactions. Hirshfeld surface analysis was employed in order to study intermolecular interactions.